docs: def cleanup(self):
          "Purpose: Frees the GL resources for a render model"
          if self.m_glVertBuffer != 0:
              glDeleteBuffers(1, (self.m_glIndexBuffer,))
              glDeleteVertexArrays( 1, (self.m_glVertArray,) )
              glDeleteBuffers(1, (self.m_glVertBuffer,))
              self.m_glIndexBuffer = 0
              self.m_glVertArray = 0
              self.m_glVertBuffer = 0